Load-Transfer Device For Reinforcing Concrete Structures

ABSTRACT

A load-transfer device for a structure comprises a top member, a bottom member and at least one web member. The top member comprises a bottom surface adapted to receive a top surface of the structure. The bottom member comprises a top surface adapted to receive a bottom surface of the structure. Each web member comprises at least one aperture extending through the web member between the bottom surface of the top member and the top surface of the bottom member. Each aperture is capable of receiving a bolt member that is capable of fastening at least one of the top member, the bottom member or combinations thereof to the web member.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

The present patent application claims priority to U.S. ProvisionalPatent Application Ser. No. 61/056,417, entitled “Connector ForReinforcing Concrete Structure,” invented by John. L. Lytton, filed May27, 2008, and the disclosure of which is incorporated by referenceherein.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter disclosed herein is illustrated by way of example andnot by limitation in the accompanying figures in which like referencenumerals indicate similar elements and in which:

FIG. 1 depicts a cross-sectional view of an exemplary parking deckformed from concrete structures generally having a double-T-shapedcross-section;

FIG. 2A depicts a widthwise cross-sectional view of an exemplaryembodiment of a load-transfer device according to the subject matterdisclosed herein;

FIG. 2B depicts a lengthwise cross-section view of an exemplaryembodiment of a load-transfer device according to the subject matterdisclosed herein; and

FIG. 3 depicts a lengthwise cross-sectional view of an exemplaryembodiment of a load-transfer device according to the subject matterdisclosed herein in which a plurality of web members span between acorresponding pair of a top plate and a bottom plate.

DETAILED DESCRIPTION

It should be understood that the word “exemplary” as used herein means“serving as an example, instance, or illustration.” Any embodimentdescribed herein as “exemplary” is not to be construed as necessarilypreferred or advantageous over other embodiments.

The subject matter disclosed herein relates to a concrete-structureload-transfer device (or connector for reinforcing a concrete structure)as depicted by the exemplary embodiments shown in FIGS. 1-3.

FIG. 1 depicts a cross-sectional view of an exemplary parking deck 100formed from concrete structures 101 generally having a double-T-shapedcross-section. It should be understood that FIG. 1 only depicts aportion of each of two adjacent double-T concrete structures 101. Steelangles (not shown) are cast into the edge at several places along theedge of a double-T-shaped concrete structure 101. A piece of rebar iswelded between adjacent steel angles on adjacent double-T concretestructures for transferring loads between the two double-T structures.The welded rebar and the steel angles are subject to rust and corrosion,thereby making the load-transferring aspect of the welded rebar andsteel angle susceptible to failure.

A load-transfer device 200, formed from two plates that are fastenedtogether through a web connection mechanism, such that thecross-sectional shape of the load-transfer device is similar to anI-beam, functions to bridge between adjacent double-T-shaped concretestructures 101 and, in so doing, provides structural support betweenadjacent double-T-shaped concrete structures 101, and the overallparking structure 100. A number of load-transfer devices 200 are placedalong a joint between two adjacent double-T structures 101, such as inan expansion joint, to sufficiently transfer the loads between thedouble-T structures for the stresses and loads that double-T structures101 are expected to experience. Load-transfer device 200 provides anadvantage in that installation of load-transfer device 200 does notdisturb the construction that is already in place because theconstruction that is in place does not need to be broken up in order toinstall a load-transfer device 200. Moreover, installation of a numberof load-transfer devices 200 can be done in a short time period, such asovernight.

FIG. 2A depicts a widthwise cross-sectional view of an exemplaryembodiment of a load-transfer device 200 in accordance with the subjectmatter disclosed herein. FIG. 2B depicts a lengthwise cross-section viewof the exemplary embodiment of load-transfer device 200 in accordancewith the subject matter disclosed herein.

As depicted in FIGS. 2A and 2B, the exemplary embodiment of aload-transfer device 200 comprises a top plate or member 201, a bottomplate or member 202 and a web member 203. For one exemplary embodiment,the top plate 201 and the bottom plate 202 are about 8″ wide by about16″ long and about ⅜″ thick. Other plate sizes can be selected based on,but not limited to, such factors as the thicknesses of thedouble-T-shaped concrete structures for which loads are to betransferred and the stresses that the load-transfer devices are expectedto experience. Web member 203 is fastened to the underside of top plate201 in a well-known manner, for example, by welding at 204. In analternative exemplary embodiment, web member 203 and top plate 201 couldbe formed integrally, such as by forging. As yet another exemplaryalternative, the web member could be separate from the top and bottomplates, such that the load-transfer device is fastened together by thebolts.

One exemplary embodiment of web member 203 comprises three (3) apertures205. Alternatively, other exemplary embodiments provide a web membercomprising a different number than three apertures 205. Top plate 201and bottom plate 202 respectively have apertures 207 and 208 thatcorrespond to the apertures 205 of web member 203. A flathead bolt 206extends through each corresponding set of apertures 207, 205 and 208through bottom plate 202. Assembled, each bolt 206 extends throughapertures 205 of web member 203, through bottom plate 202 and isfastened by, for example, a washer 209, a nut 210 and welding. Otherexemplary embodiments fasten bottom plate 202 to the bolts usingwell-known techniques, such as by welding. In one alternative exemplaryembodiment, apertures 207 are formed as counter-sunk blind apertures sothat washer 209 and nut 210 are attached to a bolt 206 adjacent to topplate 201 without projecting substantially above top plate 201.

In another alternative exemplary embodiment, web member 203 is welded toor integrally formed with top plate 201, and studs are formed on webmember 203 on the edge adjacent to bottom plate 202 that pass throughcorresponding apertures on bottom plate 202. Bottom plate 202 isfastened to web member 203 using washers and nuts tightened onto thestuds.

A neoprene pad member 211, of which only one neoprene pad is shown inFIG. 2A, can be used between bottom plate 202 and the underside of adouble-T-shaped concrete structure (not shown in FIGS. 2A and 2B) tobetter conform load-transfer device 200 to a double-T concretestructure. It should be understood that pad member 211 could be formedfrom a suitable material other than neoprene.

Load-transfer device 200 can be made from materials that are suitablefor experiencing the loads and stresses that are expected to beexperienced by load-transfer device 200, such as, but not limited to,steel. In one exemplary embodiment, the load-transfer device is formedfrom stainless steel.

It should be understood that the shapes of the top and bottom plates canbe different from the rectangular exemplary embodiment shown. Further,it should be understood that the top and bottom plates need not be thesame size and/or the same shape. As another exemplary alternativeembodiment, the web member could be fastened in a well-known manner tothe topside of the bottom plate, such as by welding. In an alternativeexemplary embodiment, the web member and the bottom plate could beformed integrally, such as by forging.

As still another alternative exemplary embodiment, FIG. 3 depicts alengthwise cross-sectional view of an exemplary embodiment of aload-transfer device according to the subject matter disclosed herein inwhich a plurality of web members 303 span between a corresponding pairof a top plate 301 and a bottom plate 302. In particular, FIG. 3 depictsthree web member 303 spanning between a top plate 301 and a bottom plate302. Web member 303 comprises at least one aperture 305 that extendsbetween top plate 301 and bottom plate 302. It should be understood thatany number of web members 303 could span between top plate 301 andbottom plate 302.

A flathead bolt 306 extends through each aperture 305 to and throughbottom plate 302. Top plate 301 and bottom plate 302 respectively haveapertures 307 and 308 that correspond to the apertures 305 of webmembers 303. Assembled, each bolt 306 extends through apertures 305 ofthe web members, through bottom plate 302 and is fastened by, forexample, a washer 309, a nut 310 and welding. It should be understoodthat each web member 303 could have any number of apertures 305. Otherexemplary embodiments fasten bottom plate 302 to the bolts usingwell-known techniques, such as by welding.

As a further alternative exemplary embodiment, a single web member couldspan between at least two sets of corresponding pairs of top and bottomplates to form a load-transfer device.

Another exemplary embodiment comprises one or more reinforcing members,such as reinforcing bar (commonly known as “rebar), a mesh and/or a gridof material could be positioned around the load-transfer devicedisclosed herein and extending into the adjacent double-T structures forfurther structural integrity between two adjacent double-T structures.

Additionally, while the exemplary embodiment depicted in FIGS. 1, 2A and2B is shown as having a non-beveled top plate, it should be understoodthat the top plate could be beveled and/or sloped at the outer edges.

One exemplary embodiment provides that the load-transfer device of thesubject matter disclosed herein is placed directly on top of the formedsurface of, for example, a parking deck floor. Another exemplaryembodiment provides that the load-transfer device of the subject matterdisclosed herein is placed within a shallow hole formed in the surfaceof two adjacent double-T structures so that the top surface of the topplate is substantially level with the top surfaces of the two adjacentdouble-T structures. Yet another exemplary embodiment provides that theload-transfer device of the subject matter disclosed herein and one ormore reinforcing members are placed within a shallow hole formed in thesurface of two adjacent double-T structures so that the top surface ofthe top plate is substantially level with the top surfaces of the twoadjacent double-T structures. The hole is then resurfaced in awell-known manner with a suitable fill material so that the suitablefill material and the top plate are substantially level with the topsurfaces of the two adjacent double-T structures.

It should be understood that the load-transfer device disclosed hereinis not limited in use with double-T concrete structures, but can be usedfor reinforcing other suitable structures.

Although the foregoing disclosed subject matter has been described insome detail for purposes of clarity of understanding, it will beapparent that certain changes and modifications may be practiced thatare within the scope of the disclosed subject matter. Accordingly, thepresent embodiments are to be considered as illustrative and notrestrictive, and the subject matter disclosed herein is not to belimited to the details given herein, but may be modified within thescope and equivalents of the disclosed subject matter.

1. A load-transfer device for a structure, comprising a top membercomprising a bottom surface adapted to receive a top surface of thestructure; a bottom member comprising a top surface adapted to receive abottom surface of the structure; and at least one web member disposedbetween the bottom surface of the top member and the top surface of thebottom member, each web member comprising at least one apertureextending through the web member between the bottom surface of the topmember and the top surface of the bottom member, each aperture capableof receiving a bolt member that is capable of fastening at least one ofthe top member, the bottom member or combinations thereof to the webmember.
 2. The load-transfer device according to claim 1, wherein atleast one web member is welded to the top member.
 3. The load-transferdevice according to claim 1, wherein at least one web member isintegrally forged with the top member.
 4. The load-transfer deviceaccording to claim 1, wherein at least one web member is welded to thebottom member.
 5. The load-transfer device according to claim 1, whereinat least one web member is integrally forged with the bottom member. 6.The load-transfer device according to claim 1, wherein the top member,the bottom member and the web member are formed from stainless steel. 7.The load-transfer device according to claim 1, further comprising a boltmember received in each aperture extending through the web memberbetween the bottom surface of the top member and the top surface of thebottom member.
 8. The load-transfer device according to claim 1, furthercomprising at least one pad member disposed between the top surface ofthe bottom member and the bottom surface of the structure.
 9. Theload-transfer device according to claim 1, wherein the structurecomprises two adjacent double-T-shaped concrete structures.
 10. Theload-transfer device according to claim 9, wherein the structurecomprises a parking deck structure.
 11. The load-transfer deviceaccording to claim 10, wherein the load-transfer device is disposed inan expansion joint of the parking deck structure.
 12. A load-transferdevice for a structure, comprising a top member comprising a bottomsurface adapted to receive a top surface of the structure; a bottommember comprising a top surface adapted to receive a bottom surface ofthe structure; and at least one web member disposed between the bottomsurface of the top member and the top surface of the bottom member, eachweb member comprising at least one stud member capable of extendingthrough an aperture extending through at least one of the top member andthe bottom member, each stud member capable of receiving a bolt memberthat is capable of fastening at least one of the top member, the bottommember or combinations thereof to the web member.